1. Field of the Invention
The present invention relates to an image-processing apparatus which is capable of performing required image processing in accordance with a changeable resolution mode. The invention also pertains to an image-processing method used in the above type of apparatus and to a display system formed by using the above type of apparatus.
2. Description of the Related Art
In television receivers, for example, in addition to the known display screens with an aspect ratio of 4:3, display screens with an aspect ratio of 16:9, which are generally referred to as "wide screens" are now widely used. Accordingly, the number of video-picture broadcast and software programs compatible with wide screens is increasing.
Moreover, along with the widespread use of personal computers, multimedia equipment operable based on a computer operating system (OS), which contains disk players compatible with various types of disk media and communication terminal capabilities, such as the Internet, are now available as one form of computer.
Therefore, monitors that are able to display images output from the above-described multimedia equipment are now being developed. Such monitors should at least be capable of receiving RGB signals output from computers and video signals, such as composite signals (and S video signals) associated with a normal television system and of displaying the resulting image.
The above type of monitor is thus able to display video images according to a standard television system, such as the NTSC method, and also to receive RGB signals output from the foregoing multimedia equipment, and to display the resulting image. It is therefore possible to construct a multimedia-capable monitor that is suitably used for both broadcast media or video image media, which output video image signals according to a standard television system, and for personal computers or multimedia equipment, which output RGB signals.
Additionally, in response to the above-described wide screens, multimedia-capable monitors having a display size in accordance with an aspect ratio of 16:9 are now being developed.
In currently available personal computers, the resolution, which is the graphic display standard represented by the number of horizontal pixels by the number of vertical pixels, being used corresponds to an aspect ratio of 4:3, and the resolution corresponding to an aspect ratio of 16:9 has not yet been determined. Thus, in the foregoing computers or multimedia equipment operable based on a computer OS, images are unfavorably output on display screens which are only effective for an aspect ratio of 4:3.
Further, when the above type of computer or multimedia equipment is combined with the foregoing multimedia-capable monitor provided with a display screen having an aspect ratio of 16:9, only the display area corresponding to an aspect ratio of 4:3 is used, and the whole display area with an aspect ratio of 16:9 cannot be effectively utilized.
In light of the foregoing background, it is expected in the computer field as well as in broadcast media that images will be displayed based on the resolution with an aspect ratio of 16:9.
However, the following problem is still present even if the resolution for graphic display can be switched between aspect ratios of 4:3 and 16:9. If a user-interface picture (hereinafter simply referred to as "the UI picture") that has been set for the resolution of the aspect ratio of 4:3 is displayed in accordance with the resolution with an aspect ratio of 16:9, the UI picture is unfavorably displayed in the effective display area with a smaller size than that which would be displayed with an aspect ratio of 4:3, thus making the user feel uncomfortable.
One of the countermeasures to the above drawback may be to execute image processing on the UI picture data in accordance with an aspect ratio of 16:9, for example, to widen the horizontal length of the UI picture. The resulting UI picture is however distorted by extending in the horizontal direction. The displayed UI picture thus appears different from the original image and appears rough in terms of resolution, thereby impairing the appearance from an aesthetic point of view.